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/*
 *******************************************************************************
 * Copyright (C) 2008-2016, Google Inc, International Business Machines Corporation
 * and others. All Rights Reserved.
 *******************************************************************************
 */
package com.ibm.icu.text;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;

import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.text.AlphabeticIndex.Bucket;
import com.ibm.icu.text.AlphabeticIndex.Bucket.LabelType;
import com.ibm.icu.util.LocaleData;
import com.ibm.icu.util.ULocale;

/**
 * AlphabeticIndex supports the creation of a UI index appropriate for a given language.
 * It can support either direct use, or use with a client that doesn't support localized collation.
 * The following is an example of what an index might look like in a UI:
 *
 * 
 *  ... A B C D E F G H I J K L M N O P Q R S T U V W X Y Z  ...
 *
 *  A
 *     Addison
 *     Albertson
 *     Azensky
 *  B
 *     Baecker
 *  ...
 * 
* * The class can generate a list of labels for use as a UI "index", that is, a list of * clickable characters (or character sequences) that allow the user to see a segment * (bucket) of a larger "target" list. That is, each label corresponds to a bucket in * the target list, where everything in the bucket is greater than or equal to the character * (according to the locale's collation). Strings can be added to the index; * they will be in sorted order in the right bucket. *

* The class also supports having buckets for strings before the first (underflow), * after the last (overflow), and between scripts (inflow). For example, if the index * is constructed with labels for Russian and English, Greek characters would fall * into an inflow bucket between the other two scripts. * *

Note: If you expect to have a lot of ASCII or Latin characters * as well as characters from the user's language, * then it is a good idea to call addLabels(ULocale.English). * *

Direct Use

*

The following shows an example of building an index directly. * The "show..." methods below are just to illustrate usage. * *

 * // Create a simple index where the values for the strings are Integers, and add the strings
 * 
 * AlphabeticIndex<Integer> index = new AlphabeticIndex<Integer>(desiredLocale).addLabels(additionalLocale);
 * int counter = 0;
 * for (String item : test) {
 *     index.addRecord(item, counter++); 
 * }
 * ...
 * // Show index at top. We could skip or gray out empty buckets
 * 
 * for (AlphabeticIndex.Bucket<Integer> bucket : index) {
 *     if (showAll || bucket.size() != 0) {
 *         showLabelAtTop(UI, bucket.getLabel());
 *     }
 * }
 *  ...
 * // Show the buckets with their contents, skipping empty buckets
 * 
 * for (AlphabeticIndex.Bucket<Integer> bucket : index) {
 *     if (bucket.size() != 0) {
 *         showLabelInList(UI, bucket.getLabel());
 *         for (AlphabeticIndex.Record<Integer> item : bucket) {
 *             showIndexedItem(UI, item.getName(), item.getData());
 *         }
 * 
* * The caller can build different UIs using this class. * For example, an index character could be omitted or grayed-out * if its bucket is empty. Small buckets could also be combined based on size, such as: * *
 * ... A-F G-N O-Z ...
 * 
* *

Client Support

*

Callers can also use the {@link AlphabeticIndex.ImmutableIndex}, or the AlphabeticIndex itself, * to support sorting on a client that doesn't support AlphabeticIndex functionality. * *

The ImmutableIndex is both immutable and thread-safe. * The corresponding AlphabeticIndex methods are not thread-safe because * they "lazily" build the index buckets. *

    *
  • ImmutableIndex.getBucket(index) provides random access to all * buckets and their labels and label types. *
  • AlphabeticIndex.getBucketLabels() or the bucket iterator on either class * can be used to get a list of the labels, * such as "...", "A", "B",..., and send that list to the client. *
  • When the client has a new name, it sends that name to the server. * The server needs to call the following methods, * and communicate the bucketIndex and collationKey back to the client. * *
     * int bucketIndex = index.getBucketIndex(name);
     * String label = immutableIndex.getBucket(bucketIndex).getLabel();  // optional
     * RawCollationKey collationKey = collator.getRawCollationKey(name, null);
     * 
    * *
  • The client would put the name (and associated information) into its bucket for bucketIndex. The collationKey is a * sequence of bytes that can be compared with a binary compare, and produce the right localized result.
  • *
* * @author Mark Davis * @stable ICU 4.8 */ public final class AlphabeticIndex implements Iterable> { /** * Prefix string for Chinese index buckets. * See http://unicode.org/repos/cldr/trunk/specs/ldml/tr35-collation.html#Collation_Indexes */ private static final String BASE = "\uFDD0"; private static final char CGJ = '\u034F'; private static final Comparator binaryCmp = new UTF16.StringComparator(true, false, 0); private final RuleBasedCollator collatorOriginal; private final RuleBasedCollator collatorPrimaryOnly; private RuleBasedCollator collatorExternal; // Comparator for records, so that the Record class can be static. private final Comparator> recordComparator = new Comparator>() { public int compare(Record o1, Record o2) { return collatorOriginal.compare(o1.name, o2.name); } }; private final List firstCharsInScripts; // We accumulate these as we build up the input parameters private final UnicodeSet initialLabels = new UnicodeSet(); private List> inputList; // Lazy evaluated: null means that we have not built yet. private BucketList buckets; private String overflowLabel = "\u2026"; private String underflowLabel = "\u2026"; private String inflowLabel = "\u2026"; /** * Immutable, thread-safe version of {@link AlphabeticIndex}. * This class provides thread-safe methods for bucketing, * and random access to buckets and their properties, * but does not offer adding records to the index. * * @param The Record value type is unused. It can be omitted for this class * if it was omitted for the AlphabeticIndex that built it. * @stable ICU 51 */ public static final class ImmutableIndex implements Iterable> { private final BucketList buckets; private final Collator collatorPrimaryOnly; private ImmutableIndex(BucketList bucketList, Collator collatorPrimaryOnly) { this.buckets = bucketList; this.collatorPrimaryOnly = collatorPrimaryOnly; } /** * Returns the number of index buckets and labels, including underflow/inflow/overflow. * * @return the number of index buckets * @stable ICU 51 */ public int getBucketCount() { return buckets.getBucketCount(); } /** * Finds the index bucket for the given name and returns the number of that bucket. * Use {@link #getBucket(int)} to get the bucket's properties. * * @param name the string to be sorted into an index bucket * @return the bucket number for the name * @stable ICU 51 */ public int getBucketIndex(CharSequence name) { return buckets.getBucketIndex(name, collatorPrimaryOnly); } /** * Returns the index-th bucket. Returns null if the index is out of range. * * @param index bucket number * @return the index-th bucket * @stable ICU 51 */ public Bucket getBucket(int index) { if (0 <= index && index < buckets.getBucketCount()) { return buckets.immutableVisibleList.get(index); } else { return null; } } /** * {@inheritDoc} * @stable ICU 51 */ public Iterator> iterator() { return buckets.iterator(); } } /** * Create the index object. * * @param locale * The locale for the index. * @stable ICU 4.8 */ public AlphabeticIndex(ULocale locale) { this(locale, null); } /** * Create the index object. * * @param locale * The locale for the index. * @stable ICU 4.8 */ public AlphabeticIndex(Locale locale) { this(ULocale.forLocale(locale), null); } /** * Create an AlphabeticIndex that uses a specific collator. * *

The index will be created with no labels; the addLabels() function must be called * after creation to add the desired labels to the index. * *

The index will work directly with the supplied collator. If the caller will need to * continue working with the collator it should be cloned first, so that the * collator provided to the AlphabeticIndex remains unchanged after creation of the index. * * @param collator The collator to use to order the contents of this index. * @stable ICU 51 */ public AlphabeticIndex(RuleBasedCollator collator) { this(null, collator); } /** * Internal constructor containing implementation used by public constructors. */ private AlphabeticIndex(ULocale locale, RuleBasedCollator collator) { collatorOriginal = collator != null ? collator : (RuleBasedCollator) Collator.getInstance(locale); try { collatorPrimaryOnly = collatorOriginal.cloneAsThawed(); } catch (Exception e) { // should never happen throw new IllegalStateException("Collator cannot be cloned", e); } collatorPrimaryOnly.setStrength(Collator.PRIMARY); collatorPrimaryOnly.freeze(); firstCharsInScripts = getFirstCharactersInScripts(); Collections.sort(firstCharsInScripts, collatorPrimaryOnly); // Guard against a degenerate collator where // some script boundary strings are primary ignorable. for (;;) { if (firstCharsInScripts.isEmpty()) { throw new IllegalArgumentException( "AlphabeticIndex requires some non-ignorable script boundary strings"); } if (collatorPrimaryOnly.compare(firstCharsInScripts.get(0), "") == 0) { firstCharsInScripts.remove(0); } else { break; } } // Chinese index characters, which are specific to each of the several Chinese tailorings, // take precedence over the single locale data exemplar set per language. if (!addChineseIndexCharacters() && locale != null) { addIndexExemplars(locale); } } /** * Add more index characters (aside from what are in the locale) * @param additions additional characters to add to the index, such as A-Z. * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex addLabels(UnicodeSet additions) { initialLabels.addAll(additions); buckets = null; return this; } /** * Add more index characters (aside from what are in the locale) * @param additions additional characters to add to the index, such as those in Swedish. * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex addLabels(ULocale... additions) { for (ULocale addition : additions) { addIndexExemplars(addition); } buckets = null; return this; } /** * Add more index characters (aside from what are in the locale) * @param additions additional characters to add to the index, such as those in Swedish. * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex addLabels(Locale... additions) { for (Locale addition : additions) { addIndexExemplars(ULocale.forLocale(addition)); } buckets = null; return this; } /** * Set the overflow label * @param overflowLabel see class description * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex setOverflowLabel(String overflowLabel) { this.overflowLabel = overflowLabel; buckets = null; return this; } /** * Get the default label used in the IndexCharacters' locale for underflow, eg the last item in: X Y Z ... * * @return underflow label * @stable ICU 4.8 */ public String getUnderflowLabel() { return underflowLabel; // TODO get localized version } /** * Set the underflowLabel label * @param underflowLabel see class description * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex setUnderflowLabel(String underflowLabel) { this.underflowLabel = underflowLabel; buckets = null; return this; } /** * Get the default label used in the IndexCharacters' locale for overflow, eg the first item in: ... A B C * * @return overflow label * @stable ICU 4.8 */ public String getOverflowLabel() { return overflowLabel; // TODO get localized version } /** * Set the inflowLabel label * @param inflowLabel see class description * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex setInflowLabel(String inflowLabel) { this.inflowLabel = inflowLabel; buckets = null; return this; } /** * Get the default label used for abbreviated buckets between other labels. For example, consider the labels * for Latin and Greek are used: X Y Z ... Α Β Γ. * * @return inflow label * @stable ICU 4.8 */ public String getInflowLabel() { return inflowLabel; // TODO get localized version } /** * Get the limit on the number of labels in the index. The number of buckets can be slightly larger: see getBucketCount(). * * @return maxLabelCount maximum number of labels. * @stable ICU 4.8 */ public int getMaxLabelCount() { return maxLabelCount; } /** * Set a limit on the number of labels in the index. The number of buckets can be slightly larger: see * getBucketCount(). * * @param maxLabelCount Set the maximum number of labels. Currently, if the number is exceeded, then every * nth item is removed to bring the count down. A more sophisticated mechanism may be available in the * future. * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex setMaxLabelCount(int maxLabelCount) { this.maxLabelCount = maxLabelCount; buckets = null; return this; } /** * Determine the best labels to use. This is based on the exemplars, but we also process to make sure that they are unique, * and sort differently, and that the overall list is small enough. */ private List initLabels() { Normalizer2 nfkdNormalizer = Normalizer2.getNFKDInstance(); List indexCharacters = new ArrayList(); String firstScriptBoundary = firstCharsInScripts.get(0); String overflowBoundary = firstCharsInScripts.get(firstCharsInScripts.size() - 1); // We make a sorted array of elements. // Some of the input may be redundant. // That is, we might have c, ch, d, where "ch" sorts just like "c", "h". // We filter out those cases. for (String item : initialLabels) { boolean checkDistinct; if (!UTF16.hasMoreCodePointsThan(item, 1)) { checkDistinct = false; } else if(item.charAt(item.length() - 1) == '*' && item.charAt(item.length() - 2) != '*') { // Use a label if it is marked with one trailing star, // even if the label string sorts the same when all contractions are suppressed. item = item.substring(0, item.length() - 1); checkDistinct = false; } else { checkDistinct = true; } if (collatorPrimaryOnly.compare(item, firstScriptBoundary) < 0) { // Ignore a primary-ignorable or non-alphabetic index character. } else if (collatorPrimaryOnly.compare(item, overflowBoundary) >= 0) { // Ignore an index character that will land in the overflow bucket. } else if (checkDistinct && collatorPrimaryOnly.compare(item, separated(item)) == 0) { // Ignore a multi-code point index character that does not sort distinctly // from the sequence of its separate characters. } else { int insertionPoint = Collections.binarySearch(indexCharacters, item, collatorPrimaryOnly); if (insertionPoint < 0) { indexCharacters.add(~insertionPoint, item); } else { String itemAlreadyIn = indexCharacters.get(insertionPoint); if (isOneLabelBetterThanOther(nfkdNormalizer, item, itemAlreadyIn)) { indexCharacters.set(insertionPoint, item); } } } } // if the result is still too large, cut down to maxLabelCount elements, by removing every nth element final int size = indexCharacters.size() - 1; if (size > maxLabelCount) { int count = 0; int old = -1; for (Iterator it = indexCharacters.iterator(); it.hasNext();) { ++count; it.next(); final int bump = count * maxLabelCount / size; if (bump == old) { it.remove(); } else { old = bump; } } } return indexCharacters; } private static String fixLabel(String current) { if (!current.startsWith(BASE)) { return current; } int rest = current.charAt(BASE.length()); if (0x2800 < rest && rest <= 0x28FF) { // stroke count return (rest-0x2800) + "\u5283"; } return current.substring(BASE.length()); } /** * This method is called to get the index exemplars. Normally these come from the locale directly, * but if they aren't available, we have to synthesize them. */ private void addIndexExemplars(ULocale locale) { UnicodeSet exemplars = LocaleData.getExemplarSet(locale, 0, LocaleData.ES_INDEX); if (exemplars != null) { initialLabels.addAll(exemplars); return; } // The locale data did not include explicit Index characters. // Synthesize a set of them from the locale's standard exemplar characters. exemplars = LocaleData.getExemplarSet(locale, 0, LocaleData.ES_STANDARD); exemplars = exemplars.cloneAsThawed(); // question: should we add auxiliary exemplars? if (exemplars.containsSome('a', 'z') || exemplars.size() == 0) { exemplars.addAll('a', 'z'); } if (exemplars.containsSome(0xAC00, 0xD7A3)) { // Hangul syllables // cut down to small list exemplars.remove(0xAC00, 0xD7A3). add(0xAC00).add(0xB098).add(0xB2E4).add(0xB77C). add(0xB9C8).add(0xBC14).add(0xC0AC).add(0xC544). add(0xC790).add(0xCC28).add(0xCE74).add(0xD0C0). add(0xD30C).add(0xD558); } if (exemplars.containsSome(0x1200, 0x137F)) { // Ethiopic block // cut down to small list // make use of the fact that Ethiopic is allocated in 8's, where // the base is 0 mod 8. UnicodeSet ethiopic = new UnicodeSet("[[:Block=Ethiopic:]&[:Script=Ethiopic:]]"); UnicodeSetIterator it = new UnicodeSetIterator(ethiopic); while (it.next() && it.codepoint != UnicodeSetIterator.IS_STRING) { if ((it.codepoint & 0x7) != 0) { exemplars.remove(it.codepoint); } } } // Upper-case any that aren't already so. // (We only do this for synthesized index characters.) for (String item : exemplars) { initialLabels.add(UCharacter.toUpperCase(locale, item)); } } /** * Add Chinese index characters from the tailoring. */ private boolean addChineseIndexCharacters() { UnicodeSet contractions = new UnicodeSet(); try { collatorPrimaryOnly.internalAddContractions(BASE.charAt(0), contractions); } catch (Exception e) { return false; } if (contractions.isEmpty()) { return false; } initialLabels.addAll(contractions); for (String s : contractions) { assert(s.startsWith(BASE)); char c = s.charAt(s.length() - 1); if (0x41 <= c && c <= 0x5A) { // A-Z // There are Pinyin labels, add ASCII A-Z labels as well. initialLabels.add(0x41, 0x5A); // A-Z break; } } return true; } /** * Return the string with interspersed CGJs. Input must have more than 2 codepoints. *

This is used to test whether contractions sort differently from their components. */ private String separated(String item) { StringBuilder result = new StringBuilder(); // add a CGJ except within surrogates char last = item.charAt(0); result.append(last); for (int i = 1; i < item.length(); ++i) { char ch = item.charAt(i); if (!UCharacter.isHighSurrogate(last) || !UCharacter.isLowSurrogate(ch)) { result.append(CGJ); } result.append(ch); last = ch; } return result.toString(); } /** * Builds an immutable, thread-safe version of this instance, without data records. * * @return an immutable index instance * @stable ICU 51 */ public ImmutableIndex buildImmutableIndex() { // The current AlphabeticIndex Java code never modifies the bucket list once built. // If it contains no records, we can use it. // addRecord() sets buckets=null rather than inserting the new record into it. BucketList immutableBucketList; if (inputList != null && !inputList.isEmpty()) { // We need a bucket list with no records. immutableBucketList = createBucketList(); } else { if (buckets == null) { buckets = createBucketList(); } immutableBucketList = buckets; } return new ImmutableIndex(immutableBucketList, collatorPrimaryOnly); } /** * Get the labels. * * @return The list of bucket labels, after processing. * @stable ICU 4.8 */ public List getBucketLabels() { initBuckets(); ArrayList result = new ArrayList(); for (Bucket bucket : buckets) { result.add(bucket.getLabel()); } return result; } /** * Get a clone of the collator used internally. Note that for performance reasons, the clone is only done once, and * then stored. The next time it is accessed, the same instance is returned. *

* Don't use this method across threads if you are changing the settings on the collator, at least not without * synchronizing. * * @return a clone of the collator used internally * @stable ICU 4.8 */ public RuleBasedCollator getCollator() { if (collatorExternal == null) { try { collatorExternal = (RuleBasedCollator) (collatorOriginal.clone()); } catch (Exception e) { // should never happen throw new IllegalStateException("Collator cannot be cloned", e); } } return collatorExternal; } /** * Add a record (name and data) to the index. The name will be used to sort the items into buckets, and to sort * within the bucket. Two records may have the same name. When they do, the sort order is according to the order added: * the first added comes first. * * @param name * Name, such as a name * @param data * Data, such as an address or link * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex addRecord(CharSequence name, V data) { // TODO instead of invalidating, just add to unprocessed list. buckets = null; // invalidate old bucketlist if (inputList == null) { inputList = new ArrayList>(); } inputList.add(new Record(name, data)); return this; } /** * Get the bucket number for the given name. This routine permits callers to implement their own bucket handling * mechanisms, including client-server handling. For example, when a new name is created on the client, it can ask * the server for the bucket for that name, and the sortkey (using getCollator). Once the client has that * information, it can put the name into the right bucket, and sort it within that bucket, without having access to * the index or collator. *

* Note that the bucket number (and sort key) are only valid for the settings of the current AlphabeticIndex; if * those are changed, then the bucket number and sort key must be regenerated. * * @param name * Name, such as a name * @return the bucket index for the name * @stable ICU 4.8 */ public int getBucketIndex(CharSequence name) { initBuckets(); return buckets.getBucketIndex(name, collatorPrimaryOnly); } /** * Clear the index. * * @return this, for chaining * @stable ICU 4.8 */ public AlphabeticIndex clearRecords() { if (inputList != null && !inputList.isEmpty()) { inputList.clear(); buckets = null; } return this; } /** * Return the number of buckets in the index. This will be the same as the number of labels, plus buckets for the underflow, overflow, and inflow(s). * * @return number of buckets * @stable ICU 4.8 */ public int getBucketCount() { initBuckets(); return buckets.getBucketCount(); } /** * Return the number of records in the index: that is, the total number of distinct <name,data> pairs added with addRecord(...), over all the buckets. * * @return total number of records in buckets * @stable ICU 4.8 */ public int getRecordCount() { return inputList != null ? inputList.size() : 0; } /** * Return an iterator over the buckets. * * @return iterator over buckets. * @stable ICU 4.8 */ public Iterator> iterator() { initBuckets(); return buckets.iterator(); } /** * Creates an index, and buckets and sorts the list of records into the index. */ private void initBuckets() { if (buckets != null) { return; } buckets = createBucketList(); if (inputList == null || inputList.isEmpty()) { return; } // Sort the records by name. // Stable sort preserves input order of collation duplicates. Collections.sort(inputList, recordComparator); // Now, we traverse all of the input, which is now sorted. // If the item doesn't go in the current bucket, we find the next bucket that contains it. // This makes the process order n*log(n), since we just sort the list and then do a linear process. // However, if the user adds an item at a time and then gets the buckets, this isn't efficient, so // we need to improve it for that case. Iterator> bucketIterator = buckets.fullIterator(); Bucket currentBucket = bucketIterator.next(); Bucket nextBucket; String upperBoundary; if (bucketIterator.hasNext()) { nextBucket = bucketIterator.next(); upperBoundary = nextBucket.lowerBoundary; } else { nextBucket = null; upperBoundary = null; } for (Record r : inputList) { // if the current bucket isn't the right one, find the one that is // We have a special flag for the last bucket so that we don't look any further while (upperBoundary != null && collatorPrimaryOnly.compare(r.name, upperBoundary) >= 0) { currentBucket = nextBucket; // now reset the boundary that we compare against if (bucketIterator.hasNext()) { nextBucket = bucketIterator.next(); upperBoundary = nextBucket.lowerBoundary; } else { upperBoundary = null; } } // now put the record into the bucket. Bucket bucket = currentBucket; if (bucket.displayBucket != null) { bucket = bucket.displayBucket; } if (bucket.records == null) { bucket.records = new ArrayList>(); } bucket.records.add(r); } } private int maxLabelCount = 99; /** * Returns true if one index character string is "better" than the other. * Shorter NFKD is better, and otherwise NFKD-binary-less-than is * better, and otherwise binary-less-than is better. */ private static boolean isOneLabelBetterThanOther(Normalizer2 nfkdNormalizer, String one, String other) { // This is called with primary-equal strings, but never with one.equals(other). String n1 = nfkdNormalizer.normalize(one); String n2 = nfkdNormalizer.normalize(other); int result = n1.codePointCount(0, n1.length()) - n2.codePointCount(0, n2.length()); if (result != 0) { return result < 0; } result = binaryCmp.compare(n1, n2); if (result != 0) { return result < 0; } return binaryCmp.compare(one, other) < 0; } /** * A (name, data) pair, to be sorted by name into one of the index buckets. * The user data is not used by the index implementation. * * @stable ICU 4.8 */ public static class Record { private final CharSequence name; private final V data; private Record(CharSequence name, V data) { this.name = name; this.data = data; } /** * Get the name * * @return the name * @stable ICU 4.8 */ public CharSequence getName() { return name; } /** * Get the data * * @return the data * @stable ICU 4.8 */ public V getData() { return data; } /** * Standard toString() * @stable ICU 4.8 */ public String toString() { return name + "=" + data; } } /** * An index "bucket" with a label string and type. * It is referenced by {@link AlphabeticIndex#getBucketIndex(CharSequence)} * and {@link AlphabeticIndex.ImmutableIndex#getBucketIndex(CharSequence)}, * returned by {@link AlphabeticIndex.ImmutableIndex#getBucket(int)}, * and {@link AlphabeticIndex#addRecord(CharSequence, Object)} adds a record * into a bucket according to the record's name. * * @param * Data type * @stable ICU 4.8 */ public static class Bucket implements Iterable> { private final String label; private final String lowerBoundary; private final LabelType labelType; private Bucket displayBucket; private int displayIndex; private List> records; /** * Type of the label * * @stable ICU 4.8 */ public enum LabelType { /** * Normal * @stable ICU 4.8 */ NORMAL, /** * Underflow (before the first) * @stable ICU 4.8 */ UNDERFLOW, /** * Inflow (between scripts) * @stable ICU 4.8 */ INFLOW, /** * Overflow (after the last) * @stable ICU 4.8 */ OVERFLOW } /** * Set up the bucket. * * @param label * label for the bucket * @param labelType * is an underflow, overflow, or inflow bucket * @stable ICU 4.8 */ private Bucket(String label, String lowerBoundary, LabelType labelType) { this.label = label; this.lowerBoundary = lowerBoundary; this.labelType = labelType; } /** * Get the label * * @return label for the bucket * @stable ICU 4.8 */ public String getLabel() { return label; } /** * Is a normal, underflow, overflow, or inflow bucket * * @return is an underflow, overflow, or inflow bucket * @stable ICU 4.8 */ public LabelType getLabelType() { return labelType; } /** * Get the number of records in the bucket. * * @return number of records in bucket * @stable ICU 4.8 */ public int size() { return records == null ? 0 : records.size(); } /** * Iterator over the records in the bucket * @stable ICU 4.8 */ public Iterator> iterator() { if (records == null) { return Collections.>emptyList().iterator(); } return records.iterator(); } /** * Standard toString() * @stable ICU 4.8 */ @Override public String toString() { return "{" + "labelType=" + labelType + ", " + "lowerBoundary=" + lowerBoundary + ", " + "label=" + label + "}" ; } } private BucketList createBucketList() { // Initialize indexCharacters. List indexCharacters = initLabels(); // Variables for hasMultiplePrimaryWeights(). long variableTop; if (collatorPrimaryOnly.isAlternateHandlingShifted()) { variableTop = collatorPrimaryOnly.getVariableTop() & 0xffffffffL; } else { variableTop = 0; } boolean hasInvisibleBuckets = false; // Helper arrays for Chinese Pinyin collation. @SuppressWarnings({ "rawtypes", "unchecked" }) Bucket[] asciiBuckets = new Bucket[26]; @SuppressWarnings({ "rawtypes", "unchecked" }) Bucket[] pinyinBuckets = new Bucket[26]; boolean hasPinyin = false; ArrayList> bucketList = new ArrayList>(); // underflow bucket bucketList.add(new Bucket(getUnderflowLabel(), "", LabelType.UNDERFLOW)); // fix up the list, adding underflow, additions, overflow // Insert inflow labels as needed. int scriptIndex = -1; String scriptUpperBoundary = ""; for (String current : indexCharacters) { if (collatorPrimaryOnly.compare(current, scriptUpperBoundary) >= 0) { // We crossed the script boundary into a new script. String inflowBoundary = scriptUpperBoundary; boolean skippedScript = false; for (;;) { scriptUpperBoundary = firstCharsInScripts.get(++scriptIndex); if (collatorPrimaryOnly.compare(current, scriptUpperBoundary) < 0) { break; } skippedScript = true; } if (skippedScript && bucketList.size() > 1) { // We are skipping one or more scripts, // and we are not just getting out of the underflow label. bucketList.add(new Bucket(getInflowLabel(), inflowBoundary, LabelType.INFLOW)); } } // Add a bucket with the current label. Bucket bucket = new Bucket(fixLabel(current), current, LabelType.NORMAL); bucketList.add(bucket); // Remember ASCII and Pinyin buckets for Pinyin redirects. char c; if (current.length() == 1 && 'A' <= (c = current.charAt(0)) && c <= 'Z') { asciiBuckets[c - 'A'] = bucket; } else if (current.length() == BASE.length() + 1 && current.startsWith(BASE) && 'A' <= (c = current.charAt(BASE.length())) && c <= 'Z') { pinyinBuckets[c - 'A'] = bucket; hasPinyin = true; } // Check for multiple primary weights. if (!current.startsWith(BASE) && hasMultiplePrimaryWeights(collatorPrimaryOnly, variableTop, current) && !current.endsWith("\uffff")) { // "Æ" or "Sch" etc. for (int i = bucketList.size() - 2;; --i) { Bucket singleBucket = bucketList.get(i); if (singleBucket.labelType != LabelType.NORMAL) { // There is no single-character bucket since the last // underflow or inflow label. break; } if (singleBucket.displayBucket == null && !hasMultiplePrimaryWeights(collatorPrimaryOnly, variableTop, singleBucket.lowerBoundary)) { // Add an invisible bucket that redirects strings greater than the expansion // to the previous single-character bucket. // For example, after ... Q R S Sch we add Sch\uFFFF->S // and after ... Q R S Sch Sch\uFFFF St we add St\uFFFF->S. bucket = new Bucket("", current + "\uFFFF", LabelType.NORMAL); bucket.displayBucket = singleBucket; bucketList.add(bucket); hasInvisibleBuckets = true; break; } } } } if (bucketList.size() == 1) { // No real labels, show only the underflow label. return new BucketList(bucketList, bucketList); } // overflow bucket bucketList.add(new Bucket(getOverflowLabel(), scriptUpperBoundary, LabelType.OVERFLOW)); // final if (hasPinyin) { // Redirect Pinyin buckets. Bucket asciiBucket = null; for (int i = 0; i < 26; ++i) { if (asciiBuckets[i] != null) { asciiBucket = asciiBuckets[i]; } if (pinyinBuckets[i] != null && asciiBucket != null) { pinyinBuckets[i].displayBucket = asciiBucket; hasInvisibleBuckets = true; } } } if (!hasInvisibleBuckets) { return new BucketList(bucketList, bucketList); } // Merge inflow buckets that are visually adjacent. // Iterate backwards: Merge inflow into overflow rather than the other way around. int i = bucketList.size() - 1; Bucket nextBucket = bucketList.get(i); while (--i > 0) { Bucket bucket = bucketList.get(i); if (bucket.displayBucket != null) { continue; // skip invisible buckets } if (bucket.labelType == LabelType.INFLOW) { if (nextBucket.labelType != LabelType.NORMAL) { bucket.displayBucket = nextBucket; continue; } } nextBucket = bucket; } ArrayList> publicBucketList = new ArrayList>(); for (Bucket bucket : bucketList) { if (bucket.displayBucket == null) { publicBucketList.add(bucket); } } return new BucketList(bucketList, publicBucketList); } private static class BucketList implements Iterable> { private final ArrayList> bucketList; private final List> immutableVisibleList; private BucketList(ArrayList> bucketList, ArrayList> publicBucketList) { this.bucketList = bucketList; int displayIndex = 0; for (Bucket bucket : publicBucketList) { bucket.displayIndex = displayIndex++; } immutableVisibleList = Collections.unmodifiableList(publicBucketList); } private int getBucketCount() { return immutableVisibleList.size(); } private int getBucketIndex(CharSequence name, Collator collatorPrimaryOnly) { // binary search int start = 0; int limit = bucketList.size(); while ((start + 1) < limit) { int i = (start + limit) / 2; Bucket bucket = bucketList.get(i); int nameVsBucket = collatorPrimaryOnly.compare(name, bucket.lowerBoundary); if (nameVsBucket < 0) { limit = i; } else { start = i; } } Bucket bucket = bucketList.get(start); if (bucket.displayBucket != null) { bucket = bucket.displayBucket; } return bucket.displayIndex; } /** * Private iterator over all the buckets, visible and invisible */ private Iterator> fullIterator() { return bucketList.iterator(); } /** * Iterator over just the visible buckets. */ public Iterator> iterator() { return immutableVisibleList.iterator(); // use immutable list to prevent remove(). } } private static boolean hasMultiplePrimaryWeights( RuleBasedCollator coll, long variableTop, String s) { long[] ces = coll.internalGetCEs(s); boolean seenPrimary = false; for (int i = 0; i < ces.length; ++i) { long ce = ces[i]; long p = ce >>> 32; if (p > variableTop) { // not primary ignorable if (seenPrimary) { return true; } seenPrimary = true; } } return false; } // TODO: Surely we have at least a ticket for porting these mask values to UCharacter.java?! private static final int GC_LU_MASK = 1 << UCharacter.UPPERCASE_LETTER; private static final int GC_LL_MASK = 1 << UCharacter.LOWERCASE_LETTER; private static final int GC_LT_MASK = 1 << UCharacter.TITLECASE_LETTER; private static final int GC_LM_MASK = 1 << UCharacter.MODIFIER_LETTER; private static final int GC_LO_MASK = 1 << UCharacter.OTHER_LETTER; private static final int GC_L_MASK = GC_LU_MASK|GC_LL_MASK|GC_LT_MASK|GC_LM_MASK|GC_LO_MASK; private static final int GC_CN_MASK = 1 << UCharacter.GENERAL_OTHER_TYPES; /** * Return a list of the first character in each script. Only exposed for testing. * * @return list of first characters in each script * @internal * @deprecated This API is ICU internal, only for testing. */ @Deprecated public List getFirstCharactersInScripts() { List dest = new ArrayList(200); // Fetch the script-first-primary contractions which are defined in the root collator. // They all start with U+FDD1. UnicodeSet set = new UnicodeSet(); collatorPrimaryOnly.internalAddContractions(0xFDD1, set); if (set.isEmpty()) { throw new UnsupportedOperationException( "AlphabeticIndex requires script-first-primary contractions"); } for (String boundary : set) { int gcMask = 1 << UCharacter.getType(boundary.codePointAt(1)); if ((gcMask & (GC_L_MASK | GC_CN_MASK)) == 0) { // Ignore boundaries for the special reordering groups. // Take only those for "real scripts" (where the sample character is a Letter, // and the one for unassigned implicit weights (Cn). continue; } dest.add(boundary); } return dest; } }





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